refactor(engine): retire the open_dataset_head_for_write alias

The method was a delegating twin of open_dataset_head that discarded its
table_key argument ("retained for signature stability") — a dead
parameter every caller still had to supply, and a second name for the
same open policy on the sealed TableStorage surface. Remove it from the
trait, the TableStore impl, and all call sites, which also lets the two
needs_index_work_* helpers drop their now-unused table_key parameters.

Purely mechanical; no behavior change.

crates/omnigraph/src/db/omnigraph.rs

@@ -98,7 +98,7 @@ pub struct SchemaApplyPreview {
 /// (each of which re-runs `ensure_schema_state_valid`). When absent (`None` — every
 /// non-mutate/load caller), every threaded function behaves byte-identically to
 /// before. The carrier never removes a version guard or changes which dataset version
-/// the per-table open targets: strict ops keep `open_dataset_head_for_write` +
+/// the per-table open targets: strict ops keep `open_dataset_head` +
 /// `ensure_expected_version`, and the commit-time OCC re-read still opens a fresh
 /// manifest snapshot (via `fresh_snapshot_for_branch_unchecked`) — only the redundant
 /// schema re-validation is dropped.

crates/omnigraph/src/db/omnigraph/optimize.rs

@@ -385,7 +385,7 @@ async fn optimize_one_table(
         // opaque `SnapshotHandle` via `into_dataset()` (gated to the maintenance path).
         let mut ds = db
             .storage()
-            .open_dataset_head_for_write(&table_key, &full_path, None)
+            .open_dataset_head(&full_path, None)
             .await?
             .into_dataset();
 
@@ -444,10 +444,10 @@ async fn optimize_one_table(
         // recovery and rolls back siblings).
         let needs_reindex = TableStore::has_unindexed_fragments(&ds).await?;
         let needs_index_create = if let Some(type_name) = table_key.strip_prefix("node:") {
-            super::table_ops::needs_index_work_node(db, type_name, &table_key, &full_path, None)
+            super::table_ops::needs_index_work_node(db, type_name, &full_path, None)
                 .await?
         } else {
-            super::table_ops::needs_index_work_edge(db, &table_key, &full_path, None).await?
+            super::table_ops::needs_index_work_edge(db, &full_path, None).await?
         };
         if !will_compact && !needs_reindex && !needs_index_create {
             if head_advanced {
@@ -778,7 +778,7 @@ async fn compact_internal_table(
     for attempt in 0..COMPACTION_RETRY_BUDGET {
         let handle = db
             .storage()
-            .open_dataset_head_for_write(table_key, &uri, None)
+            .open_dataset_head(&uri, None)
             .await?;
         let mut ds = handle.into_dataset();
 
@@ -911,7 +911,7 @@ pub async fn cleanup_all_tables(
                 // surfaced through `TableStorage` — see the optimize path
                 // above for the same rationale. Unwrap via `into_dataset()`.
                 let handle = storage
-                    .open_dataset_head_for_write(&table_key, &full_path, None)
+                    .open_dataset_head(&full_path, None)
                     .await?;
                 let ds = handle.into_dataset();
                 let before_version = keep_versions

crates/omnigraph/src/db/omnigraph/repair.rs

@@ -171,7 +171,7 @@ pub async fn repair_all_tables(db: &Omnigraph, options: RepairOptions) -> Result
         // unwrap the opaque handle (mirrors optimize / cleanup).
         let ds = db
             .storage()
-            .open_dataset_head_for_write(&table_key, &full_path, None)
+            .open_dataset_head(&full_path, None)
             .await?
             .into_dataset();
         let manifest_version = snapshot

crates/omnigraph/src/db/omnigraph/schema_apply.rs

@@ -587,7 +587,7 @@ where
         // of the lock-check can't quietly open the wrong HEAD here.
         let existing = db
             .storage()
-            .open_dataset_head_for_write(table_key, &dataset_uri, entry.table_branch.as_deref())
+            .open_dataset_head(&dataset_uri, entry.table_branch.as_deref())
             .await?;
         let staged = db.storage().stage_overwrite(&existing, batch).await?;
         let target_ds = db.storage().commit_staged(existing, staged).await?;
@@ -857,8 +857,7 @@ pub(super) async fn ensure_snapshot_entry_head_matches(
     let dataset_uri = db.storage().dataset_uri(&entry.table_path);
     let ds = db
         .storage()
-        .open_dataset_head_for_write(
+        .open_dataset_head(
-            &entry.table_key,
             &dataset_uri,
             entry.table_branch.as_deref(),
         )

crates/omnigraph/src/db/omnigraph/table_ops.rs

@@ -58,7 +58,7 @@ pub(super) async fn failpoint_publish_table_head_without_index_rebuild_for_test(
     let full_path = format!("{}/{}", db.root_uri, entry.table_path);
     let ds = db
         .storage()
-        .open_dataset_head_for_write(table_key, &full_path, table_branch)
+        .open_dataset_head(&full_path, table_branch)
         .await?;
     let state = db.storage().table_state(&full_path, &ds).await?;
     let update = crate::db::SubTableUpdate {
@@ -118,14 +118,7 @@ pub(super) async fn ensure_indices_for_branch(
             continue;
         }
         let full_path = format!("{}/{}", db.root_uri, entry.table_path);
-        if needs_index_work_node(
+        if needs_index_work_node(db, type_name, &full_path, entry.table_branch.as_deref()).await?
-            db,
-            type_name,
-            &table_key,
-            &full_path,
-            entry.table_branch.as_deref(),
-        )
-        .await?
         {
             recovery_pins.push(crate::db::manifest::SidecarTablePin {
                 table_key,
@@ -154,7 +147,7 @@ pub(super) async fn ensure_indices_for_branch(
             continue;
         }
         let full_path = format!("{}/{}", db.root_uri, entry.table_path);
-        if needs_index_work_edge(db, &table_key, &full_path, entry.table_branch.as_deref()).await? {
+        if needs_index_work_edge(db, &full_path, entry.table_branch.as_deref()).await? {
             recovery_pins.push(crate::db::manifest::SidecarTablePin {
                 table_key,
                 table_path: full_path,
@@ -226,7 +219,7 @@ pub(super) async fn ensure_indices_for_branch(
             },
             None => (
                 db.storage()
-                    .open_dataset_head_for_write(&table_key, &full_path, None)
+                    .open_dataset_head(&full_path, None)
                     .await?,
                 None,
             ),
@@ -274,7 +267,7 @@ pub(super) async fn ensure_indices_for_branch(
             },
             None => (
                 db.storage()
-                    .open_dataset_head_for_write(&table_key, &full_path, None)
+                    .open_dataset_head(&full_path, None)
                     .await?,
                 None,
             ),
@@ -405,13 +398,12 @@ async fn vector_column_trainable(
 pub(super) async fn needs_index_work_node(
     db: &Omnigraph,
     type_name: &str,
-    table_key: &str,
     full_path: &str,
     table_branch: Option<&str>,
 ) -> Result<bool> {
     let ds = db
         .storage()
-        .open_dataset_head_for_write(table_key, full_path, table_branch)
+        .open_dataset_head(full_path, table_branch)
         .await?;
     // Empty tables are skipped by the ensure_indices loop, so they must
     // not be pinned in the sidecar — pinning a table that produces zero
@@ -479,13 +471,12 @@ pub(super) async fn needs_index_work_node(
 /// way node tables are; see `needs_index_work_node`.
 pub(super) async fn needs_index_work_edge(
     db: &Omnigraph,
-    table_key: &str,
     full_path: &str,
     table_branch: Option<&str>,
 ) -> Result<bool> {
     let ds = db
         .storage()
-        .open_dataset_head_for_write(table_key, full_path, table_branch)
+        .open_dataset_head(full_path, table_branch)
         .await?;
     if db.storage().count_rows(&ds, None).await? == 0 {
         return Ok(false);
@@ -581,7 +572,7 @@ pub(super) async fn open_for_mutation_on_branch(
     // publisher's CAS fence), which is exactly the pinned base version. The base
     // already validated the schema contract once, and the staging reopen
     // (`reopen_for_mutation`) plus the publisher CAS in `commit_all` are the real
-    // drift guards. So skip `open_dataset_head_for_write` entirely and source the
+    // drift guards. So skip `open_dataset_head` entirely and source the
     // expected version from the pinned entry.
     //
     // Gated on `txn.is_some()`: without a txn (branch merge's `open_for_mutation`)
@@ -620,7 +611,7 @@ pub(super) async fn open_for_mutation_on_branch(
         None => {
             let ds = db
                 .storage()
-                .open_dataset_head_for_write(table_key, &full_path, None)
+                .open_dataset_head(&full_path, None)
                 .await?;
             if op_kind.strict_pre_stage_version_check() {
                 db.storage()
@@ -669,7 +660,7 @@ pub(super) async fn open_owned_dataset_for_branch_write(
         Some(branch) if branch == active_branch => {
             let ds = db
                 .storage()
-                .open_dataset_head_for_write(table_key, full_path, Some(active_branch))
+                .open_dataset_head(full_path, Some(active_branch))
                 .await?;
             if op_kind.strict_pre_stage_version_check() {
                 db.storage()
@@ -711,7 +702,7 @@ pub(super) async fn open_owned_dataset_for_branch_write(
             .await?;
             let ds = db
                 .storage()
-                .open_dataset_head_for_write(table_key, full_path, Some(active_branch))
+                .open_dataset_head(full_path, Some(active_branch))
                 .await?;
             if op_kind.strict_pre_stage_version_check() {
                 db.storage()
@@ -931,7 +922,7 @@ pub(super) async fn reopen_for_mutation(
         // [`crate::db::MutationOpKind`] for the policy rationale.
         let _ = expected_version;
         db.storage()
-            .open_dataset_head_for_write(table_key, full_path, table_branch)
+            .open_dataset_head(full_path, table_branch)
             .await
     }
 }

crates/omnigraph/src/exec/staging.rs

@@ -773,7 +773,7 @@ impl StagedMutation {
             // already-open staged handle (the #2 staging open) WITHOUT a fresh
             // `Dataset::open` — the same cheap live-HEAD probe
             // `ManifestCoordinator::probe_latest_version` uses. This replaces a
-            // redundant `open_dataset_head_for_write` (RFC-013 step 3b, collapse
+            // redundant `open_dataset_head` (RFC-013 step 3b, collapse
             // #3): the drift comparison below is byte-identical; only how `head`
             // is obtained changes (probe vs cold open).
             let head = entry

crates/omnigraph/src/storage_layer.rs

@@ -233,13 +233,6 @@ pub trait TableStorage: sealed::Sealed + Send + Sync + Debug {
         branch: Option<&str>,
     ) -> Result<SnapshotHandle>;
 
-    async fn open_dataset_head_for_write(
-        &self,
-        table_key: &str,
-        dataset_uri: &str,
-        branch: Option<&str>,
-    ) -> Result<SnapshotHandle>;
-
     async fn fork_branch_from_state(
         &self,
         dataset_uri: &str,
@@ -497,17 +490,6 @@ impl TableStorage for TableStore {
             .map(SnapshotHandle::new)
     }
 
-    async fn open_dataset_head_for_write(
-        &self,
-        table_key: &str,
-        dataset_uri: &str,
-        branch: Option<&str>,
-    ) -> Result<SnapshotHandle> {
-        TableStore::open_dataset_head_for_write(self, table_key, dataset_uri, branch)
-            .await
-            .map(SnapshotHandle::new)
-    }
-
     async fn fork_branch_from_state(
         &self,
         dataset_uri: &str,

crates/omnigraph/src/table_store.rs

@@ -222,22 +222,6 @@ impl TableStore {
         }
     }
 
-    pub async fn open_dataset_head_for_write(
-        &self,
-        table_key: &str,
-        dataset_uri: &str,
-        branch: Option<&str>,
-    ) -> Result<Dataset> {
-        // RFC-013 step 3a: open writes via the direct opener (O(1)) instead of the
-        // lance-namespace builder, which re-resolved the table's version chain
-        // O(depth) per write. The namespace is a catalog/discovery layer, not a
-        // per-open hot-path component (RFC §2.4); the manifest already holds the
-        // location, and `ensure_expected_version` still validates head == pinned
-        // for strict ops. `table_key` retained for signature stability.
-        let _ = table_key;
-        self.open_dataset_head(dataset_uri, branch).await
-    }
-
     pub async fn delete_branch(&self, dataset_uri: &str, branch: &str) -> Result<()> {
         let mut ds = crate::instrumentation::open_dataset(
             dataset_uri,
@@ -327,9 +311,7 @@ impl TableStore {
         table_key: &str,
         expected_version: u64,
     ) -> Result<Dataset> {
-        let ds = self
+        let ds = self.open_dataset_head(dataset_uri, branch).await?;
-            .open_dataset_head_for_write(table_key, dataset_uri, branch)
-            .await?;
         self.ensure_expected_version(&ds, table_key, expected_version)?;
         Ok(ds)
     }